Think wintry weather is the only thing contributing to your cold? Think again. Nutrition plays a major role in ensuring your immune system stays healthy. You wouldn’t go out in a snowstorm without a coat for protection: don’t forget to equip your body with the nutrients it needs to fight infection.

Boost Your Defenses:

1. Vitamin A

Vitamin A helps fight off infection by assisting in the production of white blood cells, which attack harmful bacteria and viruses. It also ensures your skin, mucous membranes and intestines are durable enough to prevent harmful bacteria from entering your body. Eggs, milk, liver, carrots, cantaloupe, papaya, sweet potatoes, spinach, kale, mango, apricots, and red peppers are all good sources.

  • Add dark greens—such as spinach or kale—to salads and soups
  • Substitute sweet potatoes in recipes featuring white baking potatoes
  • Buy dried apricots to keep at work instead of hitting the vending machine
  • Add cantaloupe, papaya, or mango to yogurt or cottage cheese for a snack

2. Vitamin C

Vitamin C helps skin heal from cuts and scrapes. This is particularly important during winter months because bacteria have a hard time penetrating healthy skin, which is your body’s first line of defense against pathogens. Most people only need 60 to 90 milligrams per day. The goal is prevention: studies show once you get sick, more vitamin C won’t help much. Each of the following suggestions will meet daily needs.

  • Supplement lunch or dinner with a large orange
  • Add 1 cup of fresh strawberries to a spinach salad
  • Cut up a pepper to pair with hummus or a yogurt-based vegetable dip for a snack

3. Probiotics

Probiotics are friendly bacteria that help regulate your immune system by keeping the ratio of ‘good’ versus ‘bad’ bacteria in balance. Studies have shown probiotics may help maintain your gut’s protective barrier. Foods containing probiotics include: yogurt, kefir, cheese, kimchi and miso.

  • Look for the statement “contains live and active cultures” on yogurt. (Some brands will also carry the “live and active” seal from the National Yogurt Association, which assures the product contained a specific amount of beneficial bacteria when it was made.)
  • Make your own miso salad dressing. Mix:
    • 1 tbsp miso
    • 1 tbsp rice vinegar
    • 1 tbsp lime juice
    • 3 to 4 tbsp peanut or sesame oil (add honey, chilies, and/or soy sauce for additional flavor)

4. Zinc

Even a modest deficiency of zinc can affect your ability to fight infections. More studies are needed to determine if zinc supplementation is beneficial in reducing cold symptoms, but supplements appear to boost the immune system when zinc levels are already low.

    • Include protein at dinner: 5 to 6 ounces of red meat or 6 oysters will meet daily zinc requirements
    • Snack on fortified cereal (check the nutrition facts per serving: cereals are often fortified to meet 25% of your needs)
    • Include protein with your snacks: 1 ounce of nuts, ¼ cup dried chickpeas or soy nuts, and 1 cup of yogurt all offer 10% of daily zinc requirements